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Lookup NU author(s): Dr Jane Reed,
Professor Tony Stevenson,
Emeritus Professor Steve Juggins
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Palaeolimnological data (diatoms, ostracods, foraminifera, molluscs, aquatic pollen and lithology) from a radiocarbon dated sediment core from a saline lake, the Laguna de Medina, provide the first complete record of Holocene lake-level change for southwest Spain for the last c. 9000 cal. years. The lake has always been relatively shallow but has exhibited marked fluctuations in salinity and water depth, especially in the earlier record when oscillations culminate in maximum lake levels from c. 6960-6680 cal. BP (c. 6070-5830 BP), indicating enhanced early- to mid-Holocene humidity and a mid-Holocene humidity maximum. Prolonged shallowing thereafter reflects in part increased aridity in the later Holocene. Lake desiccation followed by a c. 800-yr phase (zone 2) of major limnological change commencing at c. 8000 cal. BP (c 7200 BP), and a number of other abrupt desiccation events, are also noteworthy. The mid-Holocene maximum is consistent with widespread evidence for high lake levels around 6000 BP, but the underlying climatic mechanisms are uncertain; there is some evidence it may apply predominantly to the westerly (Atlantic) Peninsula, with earlier maxima in the east. Phases of abrupt limnological change show affinities with African data; as in African takes, the 'zone 2' phase appears to be a response to global change centred on c. 8.1-8.2 cal. BP. Other correlations made are tenuous, due partly to the lack of preservation in the upper record of some of the proxies used. Other desiccation events currently appear to be of more local significance, reflecting high decadal- to century-scale climatic variability throughout the Holocene.
Author(s): Reed JM, Stevenson AC, Juggins S
Publication type: Article
Publication status: Published
Journal: The Holocene
Print publication date: 01/01/2001
Date deposited: 04/02/2010
ISSN (print): 0959-6836
ISSN (electronic): 1477-0911
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